Abstract 2695: AutoPulse Mechanical Chest Compressions Improve ETCO2 in Victims of Out-Hospital Cardiac Arrest
End tidal carbon dioxide (ETCO2) is related to cardiac output, and thus chest compression (CC) quality, during cardiopulmonary resuscitation. This study was conducted to compare ETCO2 during AutoPulse mechanical CC (A-CC) and manual CC (M-CC) in victims of out-hospital cardiac arrest (OHCA). Three hundred twenty-five consecutive OHCA patients treated by EVAC Ambulance (Volusia County, Florida) between October 2003 and April 2006 who received either A-CC (N=125) or M-CC (N=200) and routine capnographic monitoring following endotracheal intubation were enrolled in this retrospective study. ETCO2 was sequentially measured at 4 separate times (T1:8.0 ± 6.3, T2:12.9 ± 5.5, T3:15.9 ± 5.8, and T4:18.8 ± 6.3 min from time of patient contact). ETCO2 measurements occurring after return of spontaneous circulation (ROSC) were excluded. Patient characteristics were similar in patients treated with A-CC and M-CC. ETCO2 was similar at T1 in patients treated with A-CC and M-CC but greater at later time points with A-CC (Figure⇓). The difference in ETCO2 measured at T1 and T2 (dETCO2=ETCO2 at T2-ETCO2 at T1) was significantly higher for A-CC compared with M-CC (2.0 vs. −0.8, p=0.01). Mean, minimum and maximum values of ETCO2 measured during the range of T1 to T4 were also higher for A-CC than M-CC (16 vs. 13.8, p=0.008; 12.8 vs. 10.9, p=0.02; 19.3 vs. 16.9, p=0.02, respectively). Both mean ETCO2 and dETCO2 had predictive value for ROSC-ED (emergency department) in patients treated with A-CC. ETCO2 tends to rise during A-CC and fall during M-CC in OHCA patients. Early rise in ETCO2 may predict a favorable outcome during A-CC.